package org.smart4j.framework.util;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.FileFilter;
import java.net.JarURLConnection;
import java.net.URL;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Set;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;


/**
 * 类操作工具类
 * 1.0
 */
public final class ClassUtil {
    private static final Logger LOGGER= LoggerFactory.getLogger(ClassUtil.class);
//    获取类加载器
    public static ClassLoader getClassLoader(){
        return Thread.currentThread().getContextClassLoader();
    }
//    加载类
    public static Class<?> loadClass(String className,Boolean isInitialized){
        Class<?> cls;
        try {
            cls=Class.forName(className,isInitialized,getClassLoader());
        } catch (ClassNotFoundException e) {
            LOGGER.error("load class failure",e);
            throw new RuntimeException(e);
        }
        return  cls;
    }
//    获取指定包名下的所有类
    public static Set<Class<?>> getClassSet(String packageName){
        Set<Class<?>> classSet = new HashSet<Class<?>>();
        try {
            Enumeration<URL> urls = getClassLoader().getResources(packageName.replace(".", "/"));
            while (urls.hasMoreElements()) {
                URL url = urls.nextElement();
                if(url!=null){
                    String protocol=url.getProtocol();
                    if(protocol.equals("file")){
                        String packagePath=url.getPath().replaceAll("%20","");
                        addClass(classSet,packagePath,packageName);
                    } else if(protocol.equals("jar")){
                        JarURLConnection jarURLConnection= (java.net.JarURLConnection) url.openConnection();
                        if(jarURLConnection!=null){
                            JarFile jarFile = jarURLConnection.getJarFile();
                            if(jarFile!=null){
                                Enumeration<JarEntry> jarEntries = jarFile.entries();
                                while(jarEntries.hasMoreElements()){
                                    JarEntry jarEntry = jarEntries.nextElement();
                                    String jarEntryName=jarEntry.getName();
                                    if(jarEntryName.endsWith(".class")){
                                        String className=jarEntryName.substring(0,jarEntryName.lastIndexOf(".")).replaceAll("/",".");
                                        doAddClass(classSet,className);
                                    }
                                }
                            }
                        }
                    }
                }
            }
        } catch (Exception e){
            LOGGER.error("get class set failure",e);
            throw new RuntimeException(e);
        }
        return classSet;
    }
    private static void addClass(Set<Class<?>> classSet,String packagePath,String packageName){
        File[] files=new File(packagePath).listFiles(new FileFilter() {
            public boolean accept(File file) {
                return (file.isFile()&&file.getName().endsWith(".class"))||file.isDirectory();
            }
        });
        for(File file:files){
            String fileName=file.getName();
            if(file.isFile()){
                String className=fileName.substring(0,fileName.lastIndexOf("."));
                if(StringUtil.isNotEmpty(packageName)){
                    className=packageName+"."+className;
                }
                doAddClass(classSet,className);
            } else{
                String subPackagePath=fileName;
                if(StringUtil.isNotEmpty(subPackagePath)){
                    subPackagePath=packagePath+"/"+subPackagePath;
                }
                String subPackageName=fileName;
                if(StringUtil.isNotEmpty(packageName)){
                    subPackageName=packageName+"."+subPackageName;
                }
                addClass(classSet,subPackagePath,subPackageName);
            }
        }
    }
    private static void doAddClass(Set<Class<?>> classSet,String className){
        Class<?> cls=loadClass(className,false);
        classSet.add(cls);
    }
}
